Added exception handling if an element does not exist

Author: Nils Langner

module/VisualCeption.php

@@ -210,6 +210,13 @@ private function getCoordinates ($elementId)
         $this->webDriver->executeScript('jQuery.noConflict();');
 
         $imageCoords = array ();
+
+        $elementExists = (bool) $this->webDriver->executeScript('return jQuery( "' . $elementId . '" ).length > 0;');
+
+        if( !$elementExists) {
+            throw new \Exception("The element you want to examine ('".$elementId."') was not found.");
+        }
+
         $imageCoords['offset_x'] = (string) $this->webDriver->executeScript('return jQuery( "' . $elementId . '" ).offset().left;');
         $imageCoords['offset_y'] = (string) $this->webDriver->executeScript('return jQuery( "' . $elementId . '" ).offset().top;');
         $imageCoords['width'] = (string) $this->webDriver->executeScript('return jQuery( "' . $elementId . '" ).width();');